1. Field of the Invention
This invention relates generally to delivery of media to one or more media rendering client devices, and in particular to providing conditional access to media content received by media rendering client devices from a remote media service provider.
2. Background of the Invention
Digital is rapidly replacing analog as the preferred format for the storage, transfer, and processing of media data in many applications. In the home, for example, a growing number of devices are equipped to receive and render digital media. This enables the media content represented by the media data to be played on an output device, stored on a medium, or transmitted to another device. Some of the common media rendering devices used in the home include digital-ready televisions and set-top boxes, DVD/CD players and recorders, stereo receivers, and personal computers—just to name a few.
The media content rendered in these media rendering devices can come from a variety of sources. Traditionally, as with music CDs and video DVDs, media content is purchased on a physical medium and then directly loaded onto these devices. But in addition to the traditional approach, many consumers are discovering the advantages of joining an audio and/or video subscription service. In a typical subscription service, a consumer pays a small fee to receive media content from a remote media service provider, for example using a personal computer connected to the Internet. The consumer may then render and play the received media data on the computer or on a device networked with the computer. Subscription services thus take further advantage of the abilities of digital media.
Subscription services are enhanced by the addition of a home network. Home networking systems, such as that described in the Universal Plug and Play (UPnP) standard, offer many advantages for connecting devices within a home-networked environment. By incorporating a subscription service with a home network, subscribers can receive media for any of the devices on their home network—not just for their personal computers. This offers tremendous flexibility in the way that subscribers can use their media; however, the increased flexibility brings concerns about security and the digital rights of the media content owners.
A major concern that media content owners have about subscription services is how to protect their content from unauthorized use and copying. For example, a subscriber may pay a fee to listen to a song once, but that fee may not entitle the subscriber to make a copy of the song. But with the advances in home networking, the media owners may not know whether their media is being delivered to a networked stereo system or to an attached CD burner. As such, there is no way to ensure that the delivered media is not being used for an unauthorized purpose, such as copying.
Although the importance of protecting media content is well understood, the industry has not developed a system that can adequately protect media content for a media or multimedia provider service. For example, some content protection schemes use encryption to secure the transmission of media data, but these schemes do not enable the approval by a system server for conditional access and authentication of particular media rendering devices. Accordingly, there is no safeguard in existing systems to prevent media data from being transmitted to unapproved devices and used in a way not authorized by the media owners, so a large hole remains in existing protection schemes. The need still exists, therefore, for a system that allows for protection of content delivered by an audio or video subscription service or other media provider service.